[wsbpel] Issue 123 - Proposal for vote

Hi Chris,  

I have a few comments: 
- how does the concept of IMA play along isolated scopes? If a IMA is closed within a isolated scope, when does the process sees this status change, immediately or when the isolated scope finishes? While an isolated scope is being executed that started with a open IMA, could a concurrent flow in the process close the IMA and cause a  missingRequest fault to be raised within the isolated scope? 
- onEvent and parallel for-each can only have default message exchanges, whereas scopes can also have custom message exchanges, right?

Best regards,